X-Git-Url: https://wimlib.net/git/?p=wimlib;a=blobdiff_plain;f=src%2Fheader.c;h=906d8e75cddebe5defa188ee3bba1855f82b5d6d;hp=332d350fe07a04109f3ca51decf4e6dcfd67300f;hb=b348831df3fcf7d8eb66d35e4d0cf8434e788473;hpb=30cfd915ede8a2b24b693525ff835b2f03220cc9 diff --git a/src/header.c b/src/header.c index 332d350f..906d8e75 100644 --- a/src/header.c +++ b/src/header.c @@ -38,17 +38,12 @@ #include #include - -/* WIM magic characters, translated to a single 64-bit little endian number. */ -#define WIM_MAGIC \ - cpu_to_le64(((u64)'M' << 0) | \ - ((u64)'S' << 8) | \ - ((u64)'W' << 16) | \ - ((u64)'I' << 24) | \ - ((u64)'M' << 32) | \ - ((u64)'\0' << 40) | \ - ((u64)'\0' << 48) | \ - ((u64)'\0' << 54)) +#include +#ifdef HAVE_ALLOCA_H +# include +#else +# include +#endif /* On-disk format of the WIM header. */ struct wim_header_disk { @@ -113,30 +108,72 @@ struct wim_header_disk { u8 unused[60]; } _packed_attribute; -/* Reads the header from a WIM file. */ +/* + * Reads the header from a WIM file. + * + * @filename + * Name of the WIM file (for error/debug messages only), or NULL if reading + * directly from file descriptor. + * @in_fd + * File descriptor, positioned at offset 0, to read the header from. + * @hdr + * Structure to read the header into. + * + * Return values: + * WIMLIB_ERR_SUCCESS (0) + * WIMLIB_ERR_IMAGE_COUNT + * WIMLIB_ERR_INVALID_CHUNK_SIZE + * WIMLIB_ERR_INVALID_PART_NUMBER + * WIMLIB_ERR_NOT_A_WIM_FILE + * WIMLIB_ERR_READ + * WIMLIB_ERR_UNEXPECTED_END_OF_FILE + * WIMLIB_ERR_UNKNOWN_VERSION + */ int -read_header(const tchar *filename, int in_fd, struct wim_header *hdr) +read_wim_header(const tchar *filename, struct filedes *in_fd, + struct wim_header *hdr) { struct wim_header_disk disk_hdr _aligned_attribute(8); + int ret; + tchar *pipe_str; + + wimlib_assert(in_fd->offset == 0); + + if (!filename) { + pipe_str = alloca(40); + tsprintf(pipe_str, T("[fd %d]"), in_fd->fd); + filename = pipe_str; + } BUILD_BUG_ON(sizeof(struct wim_header_disk) != WIM_HEADER_DISK_SIZE); DEBUG("Reading WIM header from \"%"TS"\"", filename); - if (full_pread(in_fd, &disk_hdr, sizeof(disk_hdr), 0) != sizeof(disk_hdr)) { - ERROR_WITH_ERRNO("\"%"TS"\": Error reading header", filename); - return WIMLIB_ERR_READ; - } + ret = full_read(in_fd, &disk_hdr, sizeof(disk_hdr)); + if (ret) + goto read_error; if (disk_hdr.magic != WIM_MAGIC) { - ERROR("\"%"TS"\": Invalid magic characters in header", filename); - return WIMLIB_ERR_NOT_A_WIM_FILE; + if (disk_hdr.magic == PWM_MAGIC) { + /* Pipable WIM: Use header at end instead, unless + * actually reading from a pipe. */ + if (!in_fd->is_pipe) { + lseek(in_fd->fd, -WIM_HEADER_DISK_SIZE, SEEK_END); + ret = full_read(in_fd, &disk_hdr, sizeof(disk_hdr)); + if (ret) + goto read_error; + } + } else { + ERROR("\"%"TS"\": Invalid magic characters in header", filename); + return WIMLIB_ERR_NOT_A_WIM_FILE; + } } + hdr->magic = disk_hdr.magic; if (le32_to_cpu(disk_hdr.hdr_size) != sizeof(struct wim_header_disk)) { ERROR("\"%"TS"\": Header size is invalid (%u bytes)", filename, le32_to_cpu(disk_hdr.hdr_size)); - return WIMLIB_ERR_INVALID_HEADER_SIZE; + return WIMLIB_ERR_INVALID_HEADER; } if (le32_to_cpu(disk_hdr.wim_version) != WIM_VERSION) { @@ -186,23 +223,27 @@ read_header(const tchar *filename, int in_fd, struct wim_header *hdr) hdr->boot_idx = le32_to_cpu(disk_hdr.boot_idx); get_resource_entry(&disk_hdr.integrity_table_res_entry, &hdr->integrity); return 0; + +read_error: + ERROR_WITH_ERRNO("\"%"TS"\": Error reading header", filename); + return ret; } -/* - * Writes the header for a WIM file. - * - * @hdr: A pointer to a struct wim_header structure that describes the header. - * @out_fd: The file descriptor to the WIM file, opened for writing. - * - * Returns zero on success, nonzero on failure. - */ +/* Writes the header for a WIM file at the specified offset. If the offset + * specified is the current one, the position is advanced by the size of the + * header. */ int -write_header(const struct wim_header *hdr, int out_fd) +write_wim_header_at_offset(const struct wim_header *hdr, struct filedes *out_fd, + off_t offset) { struct wim_header_disk disk_hdr _aligned_attribute(8); - DEBUG("Writing WIM header."); + int ret; + + DEBUG("Writing %sWIM header at offset %"PRIu64, + ((hdr->magic == PWM_MAGIC) ? "pipable " : ""), + offset); - disk_hdr.magic = WIM_MAGIC; + disk_hdr.magic = hdr->magic; disk_hdr.hdr_size = cpu_to_le32(sizeof(struct wim_header_disk)); disk_hdr.wim_version = cpu_to_le32(WIM_VERSION); disk_hdr.wim_flags = cpu_to_le32(hdr->flags); @@ -220,19 +261,38 @@ write_header(const struct wim_header *hdr, int out_fd) put_resource_entry(&hdr->integrity, &disk_hdr.integrity_table_res_entry); memset(disk_hdr.unused, 0, sizeof(disk_hdr.unused)); - if (full_pwrite(out_fd, &disk_hdr, sizeof(disk_hdr), 0) != sizeof(disk_hdr)) { + if (offset == out_fd->offset) + ret = full_write(out_fd, &disk_hdr, sizeof(disk_hdr)); + else + ret = full_pwrite(out_fd, &disk_hdr, sizeof(disk_hdr), offset); + if (ret) ERROR_WITH_ERRNO("Failed to write WIM header"); - return WIMLIB_ERR_WRITE; - } - DEBUG("Done writing WIM header"); - return 0; + return ret; +} + +/* Writes the header for a WIM file at the output file descriptor's current + * offset. */ +int +write_wim_header(const struct wim_header *hdr, struct filedes *out_fd) +{ + return write_wim_header_at_offset(hdr, out_fd, out_fd->offset); +} + +/* Update just the wim_flags field. */ +int +write_wim_header_flags(u32 hdr_flags, struct filedes *out_fd) +{ + le32 flags = cpu_to_le32(hdr_flags); + + return full_pwrite(out_fd, &flags, sizeof(flags), + offsetof(struct wim_header_disk, wim_flags)); } /* * Initializes the header for a WIM file. */ int -init_header(struct wim_header *hdr, int ctype) +init_wim_header(struct wim_header *hdr, int ctype) { memset(hdr, 0, sizeof(struct wim_header)); switch (ctype) { @@ -254,6 +314,7 @@ init_header(struct wim_header *hdr, int ctype) hdr->total_parts = 1; hdr->part_number = 1; randomize_byte_array(hdr->guid, sizeof(hdr->guid)); + hdr->magic = WIM_MAGIC; return 0; } @@ -275,11 +336,11 @@ struct hdr_flag hdr_flags[] = { {WIM_HDR_FLAG_COMPRESS_XPRESS, "COMPRESS_XPRESS"}, }; -/* Prints information from the header of the WIM file associated with @w. */ +/* API function documented in wimlib.h */ WIMLIBAPI void -wimlib_print_header(const WIMStruct *w) +wimlib_print_header(const WIMStruct *wim) { - const struct wim_header *hdr = &w->hdr; + const struct wim_header *hdr = &wim->hdr; tprintf(T("Magic Characters = MSWIM\\000\\000\\000\n")); tprintf(T("Header Size = %u\n"), WIM_HEADER_DISK_SIZE); @@ -294,8 +355,8 @@ wimlib_print_header(const WIMStruct *w) tfputs (T("GUID = "), stdout); print_byte_field(hdr->guid, WIM_GID_LEN, stdout); tputchar(T('\n')); - tprintf(T("Part Number = %hu\n"), w->hdr.part_number); - tprintf(T("Total Parts = %hu\n"), w->hdr.total_parts); + tprintf(T("Part Number = %hu\n"), wim->hdr.part_number); + tprintf(T("Total Parts = %hu\n"), wim->hdr.total_parts); tprintf(T("Image Count = %u\n"), hdr->image_count); tprintf(T("Lookup Table Size = %"PRIu64"\n"), (u64)hdr->lookup_table_res_entry.size);